Leonardo DiCaprio's new movie, "Inception," is many things, but simple is not one of them. He plays Dom Cobb, a professional safecracker, only he's trying to steal secrets from someone's mind. For a price, he will drug a high-powered CEO, slip into his dreams and track down the secrets to his empire and then sell it to a competitor.

Cobb needs a crew to pull off these capers: a chemist, a fixer, a forger and an architect to build the dream world. Here, DiCaprio tries to recruit the actress Ellen Page to join him, though she's new to his line of work.

(Soundbite of film, "Inception")

Mr. LEONARDO DiCAPRIO (Actor): (As Cobb) Let me ask you a question. You never really remember the beginning of a dream, do you? You always wind up right in the middle of what's going on.

Ms. ELLEN PAGE (Actor): (As Ariadne) I guess, yeah.

Mr. DiCAPRIO: (As Cobb) So how did we end up here?

Ms. PAGE: (As Ariadne) Well, we just came from the...

Mr. DiCAPRIO: (As Cobb) Think about it, Ariadne. How did you get here? Where are you right now?

(Soundbite of music)

Ms. PAGE: (As Ariadne) We're dreaming?

Mr. DiCAPRIO: (As Cobb) You're actually in the middle of the workshop right now. See, the thing is, this is your first lesson in shared dreaming.

NORRIS: There is, of course, a catch. Dom Cobb was once married. Marion Cotillard plays his former wife, Mal, now a menacing presence in his dreams.

I spoke with Leonardo DiCaprio. He told me that before they began shooting, he and director Christopher Nolan spent two months together, talking every day, sometimes all day, about the world of the story.

Mr. DiCAPRIO: He was very passionate and very focused on creating this emotional, cathartic back story for Cobb. So that led us to really delve deep into his past because this story is set in the present, but there's obviously things from his past that keep coming about within the dreamscape that are sabotaging the mission.

And we had to really create what that story was, and that led us to that led us to both just really creating this back story of his relationship with Mal and having, without giving away the ending, having almost lived a full life together. And there's this deeply rooted attachment that he has to her emotionally because of that.

And he's been to places that people in the I guess the waking world haven't experienced yet. And all that stuff helped really shape not only the course of the character but the whole movie and, tonally, what happens at the end because, like I said, it does become this two-and-a-half-hour psychotherapy session.

NORRIS: Did it feel like that when you were working on it?

Mr. DiCAPRIO: Very much so. You know, I use that word existential, but I've really never had conversations with other actors about scenes like I had on this film, in particular with Marion Cotillard, who is incredible to work with because not only is she an extremely talented actress, but she was really game for these types of sort of strange, philosophical conversations about ho to play a scene where I'm in essence talking to my own conscience, and she is a manifestation of my own trauma. And I'm face to face with that, but I'm also talking to another character in the film who is, in essence, my therapist within the dreamscape, and I'm talking to her about my nightmares.

But when you look at the movie, it looks like two characters just talking and a third one listening, but it's this whole different set of rules and laws that apply within this insane world that Chris Nolan created.

NORRIS: You know, I don't want to give too much away, but after watching this, I'm very conscious of falling asleep. It makes me think that I'm going to be very careful about falling asleep on a train or on a moving plane or any place where people might actually see me. And I'm wondering if you had that experience, if you started to really think about and analyze your own dreams in interesting ways.

Mr. DiCAPRIO: You know, strangely enough, I'm not a big dreamer at all. I remember...

NORRIS: Or so you think.

Mr. DiCAPRIO: I have very vivid dreams, and, you know, while I'm in them, oftentimes I know that I'm dreaming, and I tell myself to remember some of these sequences when I wake up, and then I usually forget all of them.

But I actually had one recently that was really interesting, and it's I guess because I've been talking about this damn movie so much, but doing all this publicity that I entered the dreamscape and really applied all the rules of "Inception" and all the ideas that Chris has in this movie to my dream.

And I knew I was dreaming, but I also didn't know that I had done this film, or I was in a movie about the dreamscape. And I got to manipulate it from being a horrific nightmare into something quite positive. So that was a really interesting experience.

NORRIS: So you accepted the training. You passed.

Mr. DiCAPRIO: I accepted the training. I absolutely accepted it.

NORRIS: Many of your recent and what some consider to be your best films, "The Aviator," "Departed," "Revolutionary Road," "Shutter Island" and now "Inception," are all in one way or another about the mind and a certain kind of madness. Why are you drawn to this kind of material?

Mr. DiCAPRIO: Well, certainly with these last two films, I've just been fascinated with the idea of a completely unreliable protagonist not only to the audience but to everyone around him.

And the idea that somebody could be going on their own inner journey while they're simultaneously trying to figure out some sort of mystery or simultaneously trying to explore a world that they're unfamiliar with just fascinated the hell out of me.

I've never really questioned why I'm drawn to a certain piece of material or if I've done a specific type of genre before. I always look at them as unique experiences because I believe as history unfolds, certain films will disappear, and certain ones will stand the test of time. And you never know which ones those are. And you've just got to go for the opportunities of films that you think might be memorable or might have an emotional impact on people.

NORRIS: Well, I know I have to let you go, but I just have one last, quick question. You mentioned something, that Dom Cobb experiences things in this film that people in the waking world have never known. He's a man who's isolated in part because he's so good at what he does and for one reason or another just can't go home.

It seems like as a very successful actor, that's something that you might be able to relate to.

Mr. DiCAPRIO: I do. You know, it's been interesting having worked in this industry for over 20 years now, being 35 and having started when I was, you know, 13, 14 years old. And I've gotten to go to far-off places in the world, have very unique, isolated, intense experiences for four or five months at a time, and then, kind of like a dream, those things disappear. You may see those people again, but it's never, ever going to be as intense as it was for that time period.

And you are, in essence, kind of living other people's lives. And when you do that, and when you research these characters, and you want to become emotionally invested in them, you have to, in a way, try to channel their feelings and their emotional constraints.

So it has been very much like my therapy because I get to go to places that I don't think I normally would in a lot of occurrences because my life has been pretty damned blessed thus far. I've been a pretty lucky man.

NORRIS: Well, we've been lucky to talk to you. Leonardo DiCaprio, it's been a pleasure to talk to you. Thanks so much.

Mr. DiCAPRIO: Thank you.

NORRIS: That's Leonardo DiCaprio. His latest film is "Inception."

(Soundbite of music)

NORRIS: And you'll find differing opinions of the film, from critics Kenneth Turan and David Edelstein. That's at npr.org.

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